Radiation side effects

Approximately 60% of all cancer patients receive radiation therapy, and thousands of people become cancer free after treatment. However, some are not helped by radiation therapy.

BACKGROUND

Radiation therapy is one type of treatment that uses high energy particles or waves to kill cancer cells, damaging their genetic material so they cannot continue to grow and divide. Approximately 60% of all cancer patients receive radiation therapy, and thousands of people become cancer free after treatment. However, some people are not helped by radiation therapy. Additionally, radiation therapy may be used alone or with other treatments such as chemotherapy or surgery. Radiation therapy may be used to cure or shrink early stage cancer, prevent cancer from recurring in another area, and treat symptoms of advanced cancer. It is considered a local treatment because the radiation does not reach all parts of the body and only affects cells in and around the cancer. Therefore, radiation therapy is not as useful against cancer that has spread to distant parts of the body. The radiation dose given depends on the type of cancer and whether there are tissues and organs nearby that may be damaged.

Radiation therapy may damage nearby healthy cells and side effects may occur depending on the treatment location. The goal of radiation therapy is to damage as many cancer cells as possible while limiting harm to healthy tissue. Doctors try to protect healthy cells during radiation therapy by using as low a dose as possible, spreading out treatment over time, and aiming radiation at a precise part of the body. Most side effects go away within two months after radiation therapy is finished. However, late side effects may develop six or more months after treatment completion.

CAUSES

External radiation therapy: External radiation therapy is similar to getting an x-ray and is a common cancer treatment that uses high doses of radiation to destroy cancer cells and shrink tumors. A machine aims radiation at the cancer site and passes through the skin. The treatment does not hurt, and patients will not become radioactive, or give off radiation to family and friends. Patients should lie very still on the treatment table and expect to see lights pointed at them. They should be assured that these lights are safe and help the therapist identify where to aim the radiation. Most patients receive treatment once a day for five days in a row lasting for two to ten weeks. Each session lasts for thirty minutes to one hour including waiting time. During the treatment visit, patients usually receive radiation for one to five minutes.

Internal radiation therapy (also known as brachytherapy): Internal radiation therapy allows the doctor to give a dose of radiation to a smaller area and in a shorter time than is possible with external radiation treatment. Radioactive material is sealed in small containers (implants), such as seeds, ribbons, or wires and is placed into the body using a small thin tube called a catheter to destroy the cancer cells. Sometimes an applicator or a balloon attached to a thin tube is used. There are three types of implants used: low-dose rate (LDR) implants, high-dose rate (HDR) implants, and permanent implants. The LDR implants stay in for one to seven days before they are removed. Once the implant is removed, patients are not radioactive and may be around people. The HDR implants stay in place for a few minutes at a time before being removed. Patients are not radioactive after removing the HDR implant. Permanent implants stay in the body and are not removed. They give off small doses of radiation for a few weeks to months and then slowly stop. Patients should avoid coming in close contact with children and pregnant women. The implant procedures are done in a hospital operating room, and patients will be given anesthesia, which may be either general (the patient is asleep) or regional (part of the body is numbed). Severe pain or illness is not usually experienced during treatment. Patients may feel drowsy, weak, or nauseous from the anesthesia, but these symptoms usually go away quickly. Patients may experience some discomfort if the implant is held in place by an applicator.

SIGNS AND SYMPTOMS

Alopecia: Hair loss may occur since radiation therapy damages cells that grow quickly, such as those in the hair roots. Hair loss may develop two to three weeks after the first treatment session. When hair loss occurs, patients should wear a hat or a scarf to protect the scalp. The hair may grow back three to six months after treatment. However, when very high doses of radiation are used, the hair may not grow back.

Radiation associated leukopenia: Radiation therapy may lower the body's production of white blood cells causing them to work less effectively. This occurs more frequently when patients are also receiving chemotherapy. It is important for patients and family members to recognize early signs of infection such as the following: body temperature >100.5 F, sore throat, cough or shortness of breath, nasal congestion, burning during urination, and chills. These symptoms should be reported to the doctor immediately.

Radiation dermatitis: Radiation dermatitis, also known as radiodermatitis, is a common side effect of radiation therapy. Radiation skin irritation may occur a few weeks after beginning treatment. Common skin changes include redness, itching, and swelling.

Radiation emergency: Radiation emergency, also known as radiation sickness, occurs when patients are exposed to a large amount of radiation. Signs and symptoms may include the following: nausea and vomiting, diarrhea, weakness, dehydration, hair loss, bloody stool, and bruising.

Radiation-induced mucositis: Oral mucositis is an inflammation of mucous membranes of the mouth and has been reported in approximately 60% of patients receiving radiation therapy. Oral mucositis generally occurs in patients receiving radiation therapy of the head and neck. Radiation therapy may damage the lining of the mouth, resulting in symptoms ranging from slight soreness to mouth ulcers. Sores may appear on any of the soft tissues of the lips or mouth including the gums and tongue. Patients may have significant discomfort when eating and swallowing. Symptoms usually last for six to eight weeks

Radiation-induced colitis/diarrhea: Radiation to the pelvis, stomach, and abdomen may cause diarrhea since healthy cells in the large and small bowels are affected by the treatment. Symptoms include frequent bowel movements that may be soft, formed, loose, or watery.

Radiation-induced lung damage: Chest radiation therapy may cause lung damage and lead to difficulty breathing and shortness of breath.

Radiation-associated side effects (prostate cancer): Patients receiving radiation therapy to the prostate or bladder may develop urinary or bladder problems. Symptoms include the following: burning or pain during urination, cystitis (inflammation or infection of the urinary bladder), incontinence, frequent urination, blood in the urine, and bladder spasms.

Sexual changes: Radiation therapy may cause sexual changes that affect men and women. Sexual problems for women include the following: pain or discomfort during sex, vaginal itching, burning, dryness, atrophy (when the muscles in the vagina become weak), vaginal stenosis (when the vagina becomes less elastic, narrows, and gets shorter), menopausal symptoms, and infertility. Sexual problems for men include the following: erectile dysfunction and infertility.

DIAGNOSIS

General: Radiation therapy side effects depend on the part of the body being treated and may develop a few days or weeks after therapy begins. Patients should keep in close contact with their radiation oncologist.

Leukopenia: The number of white blood cells may decrease during radiation therapy. The normal white blood cell count ranges between 4,000 and 11,000 cells per microliter. Patients with fewer than 4,000 cells are at risk for developing an infection. Unless the number of white blood cells is extremely low, patients probably will not experience any signs or symptoms. This is why the doctor will frequently monitor the white blood cells using a test called a complete blood count (CBC) by taking blood from a vein.

Radiation mucositis: Patients who receive radiation therapy of the head and neck may develop mouth sores. Damage to the cells makes it difficult for the mouth to heal and fight off bacteria, leading to sores and infection. It is important to see a dentist regularly to make sure the mouth is in good shape during treatment. Good mouth care may prevent infection, bleeding, and difficulty eating and swallowing.

Physical exam: A physical exam should be conducted including questions regarding the patient's usual bowel movement patterns, diarrhea patterns, nutritional health, and quality of life to diagnose radiation enteritis.

Radiation dermatitis: Radiation skin irritation may occur a few weeks after beginning treatment. It is important to let the doctor know of any skin changes.

COMPLICATIONS

Brain changes: Radiation therapy to the brain may cause problems months or years after treatment ends. Side effects may include memory loss, unsteadiness, or personality changes. Patients may seek help from a physical, occupational, or speech therapist.

Depression: Clinical depression occurs in approximately 25% of cancer patients since coping is difficult for patients and families. Medication and counseling may help with symptoms and increase the patient's quality of life.

Infertility: Women receiving radiation therapy to the abdomen, pelvis, vagina, or uterus may destroy eggs in the ovaries leading to premature menopause. Additionally, men receiving radiation therapy to the testicles may develop fertility problems. Different options include the following: adoption, donor sperm, donor embryos, donor eggs, or surrogacy (another woman carries and gives birth to the child).

Joint problems: Radiation therapy may cause scar tissue and weakness in areas treated for joint or bone cancer. This can lead to loss of motion in the joints. A physical therapist can provide exercises to decrease pain, increase strength, and improve movement.

Lymphedema: Radiation therapy may damage the lymph nodes (located in clusters in the neck, armpits, and groin) causing swelling of an arm or leg. Ways to manage symptoms include taking care of the arm or leg by using skin lotion, keeping the feet clean, and wearing loose fitting clothes.

Malnutrition: Mouth sores may become so severe that patients develop significant discomfort when eating and swallowing. This may cause malnutrition and dehydration, which could lead to hospitalization. Regular appointments with a dentist and taking care of the mouth may prevent malnutrition that occurs as a result of painful eating and swallowing.

Secondary cancer: Radiation therapy may cause a new cancer many years after treatment. Patients should have check-ups with a radiation oncologist for the rest of their lives.

TREATMENT

General: Several medications may help alleviate radiation therapy side effects.

Hydrolytic enzymes: Based on clinical evidence, these enzymes may protect against acute radiation side effects such as mucositis, dysphagia, (difficulty or pain when swallowing), and skin reactions.

Topical management: Moisturizing the skin with Aloe vera or vitamin E may help with dry and itchy skin. Patients should avoid exposing the area to the sun during radiation therapy and for at least one year after treatment. Hydrocortisone 1% cream may have a soothing effect in patients with skin reactions. This cream is available over-the-counter at local pharmacies. Additionally, wound dressings may help protect the skin from germs.

Thyroid protection: After a radiation emergency, radioactive iodine may be released into the air and breathed into the lungs. Radioactive iodine absorbed by the thyroid may injure the gland. Non-radioactive potassium iodide (KI) works by blocking radioactive iodine from entering the thyroid.

INTEGRATIVE THERAPIES

Strong scientific evidence:

Iodine: Potassium iodide (KI) can be given in cases of radiation exposure to block radioactive iodine uptake by the thyroid. This may reduce the risk of developing thyroid cancer in the future. Potassium iodide does not provide immediate protection from radiation damage, and does not have protective effects against other radiation exposure complications.

Good scientific evidence:

Calendula: One study in women receiving radiation therapy for breast cancer reports that calendula ointment applied to the skin at least twice daily during treatment reduces the number of people experiencing the following severe dermatitis symptoms (skin irritation, redness, and pain). However, based on study design limitations, the evidence cannot be considered conclusive. Evidence suggests that calendula ointment may be considered in patients who experience radiation dermatitis that cannot be controlled with other therapies.

Probiotics: One study suggests that Lactobacillus rhamnosus may aid in reducing symptoms of radiation-induced diarrhea in patients receiving radiotherapy for cancer in the abdomen and pelvis.

Unclear or conflicting scientific evidence:

Belladonna: Homeopathic application of belladonna for the management of radiodermatitis has been suggested based on the observed similarities between symptoms of radiodermatitis and the effects of belladonna (based on the dictum that "like cures like"). One randomized trial has reported modest benefits of a homeopathic (dilute) oral belladonna preparation for radiodermatitis. However, there is no scientific basis for this use. There is currently insufficient evidence to support the use of belladonna for the management of radiodermatitis.

Echinacea: Studies have reported mixed results, and it is unclear whether Echinacea is beneficial for leukopenia (low white blood cells) following x-ray treatment.

Ginseng: There is insufficient evidence for or against the use of Panax ginseng or American ginseng as a radioprotector (protect normal cells from being damaged during radiation). However, other clinical studies have found that ginseng may improve fatigue and well being, which are symptoms of common side effects associated with radiation therapy.

Honey: The literature revealed only one randomized controlled trial investigating the effects of honey on radiation mucositis. Better quality studies are necessary before a firm conclusion can be drawn.

Zinc: Radiation may cause mucositis, which is inflammation of mucous membranes inside the mouth, nose, and throat. Two studies suggest that zinc may lower the extent of mucositis in patients receiving radiation therapy. Further research is necessary before a firm conclusion can be drawn.

Fair negative scientific evidence:

Aloe: Reports during the 1930s of topical aloe's beneficial effect on post-radiation dermatitis triggered widespread use in dermatologic and cosmetic products. Some practitioners recommend aloe gel for radiation-induced dermatitis. However, preliminary scientific evaluation suggests that topical aloe may not significantly improve pain or desquamation (shedding of the outer layer of skin) related to radiotherapy. Additional well-designed studies are necessary before a firm conclusion can be drawn.

Pantothenic acid: One study reported that skin application of dexpanthenol, an analog of pantothenic acid, to areas of skin treated with radiation does not appear to reduce erythema (redness of the skin), desquamation (shedding of the outer layer of skin), itching, or pain following treatment.

Cordyceps sinensis: One study reports that cordyceps sinensis may provide radiation protection. Future studies are necessary before a firm conclusion can be drawn.

Holy basil: Reports suggest holy basil may provide radioprotection. Future research is necessary before a firm conclusion can be drawn.

Milk thistle: A report suggests that milk thistle may prevent radiation toxicity. Future studies with humans are necessary before a firm conclusion can be drawn.

Rutin: Reports suggest rutin may be beneficial for patients receiving radiation therapy of the head and neck who develop sialadenitis (inflammation of the salivary glands) and mucositis. Future research is necessary before a firm conclusion can be drawn.

PREVENTION

Patients should visit the dentist at least two weeks prior to receiving radiation therapy to the head or neck to see if there are any problems with the teeth and mouth before beginning treatment. Additionally, patients should check their mouth everyday for sores or infection. Caregivers may use a flashlight to check the patient's mouth for red areas. Hard foods should be mashed so that they are easier to eat. The teeth and gums should be brushed with a soft bristle brush two to three times a day for two to three minutes. The toothbrush may be rinsed in hot water every fifteen to thirty seconds to soften the bristles if needed. Mild-tasting toothpaste with fluoride should be used to reduce irritation of the mouth. Acid fruits and juices, such as tomato, orange, grapefruit, lime, or lemon should be avoided. Also, alcohol and tobacco products should be avoided since they can irritate the mouth.

Good nutrition during radiation therapy may help patients with the following factors: feeling better, keeping up their strength and energy, maintaining a healthy weight, tolerating side effects, decreasing the chance of infection, and recovering and healing as quickly as possible. Patients should eat something at least one hour before treatment. Eat small, frequent meals with fluids if food does not taste good, hurts going down, or causes diarrhea. Family members and friends may help prepare meals and do the shopping.

Patients should take good care of their skin and only use lotions and other products recommended by their physician.

Drinking six to eight cups of fluids daily may prevent urinary and bladder problems.

Patients should speak with their doctor before side effects become worse.

Some people are able to work full-time during radiation therapy. However, others may only work part-time, or not at all. Each person is different depending on what he/she is able to tolerate.

There are different ways patients may cope with their feelings during radiation therapy such as: meditation, exercise, or joining a support group.

AUTHOR INFORMATION

This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

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